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Seminar Details

Date 20-4-2007
Time 16:30
Room/Location Disi Sala Conferenze -3° piano
Title L'incompletezza logico-causale della Teoria della Programmazione in Biologia molecolare
Speaker Giuseppe Longo
Affiliation Directeur de Recherche (DR1) , CNRS & Département. d'Informatique, Ecole Normale Supérieure, France
Link http://www.disi.unige.it/person/MoggiE/ftp/Longo-2007-04-20.pdf
Abstract Since the 1930s and, more specifically, the 1950s, molecular processes in cellular reproduction have been often analyzed by the "the DNA is a program" metaphor or even model, in the physico-mathematical sense. Schroedinger by his 1944 book contributed to this understanding, but he lucidly hinted to the intended causal structure underlying the paradigm. Subsequent work by Monod, Lwoff and Jacob opened the way to a large use of this model or metaphor, as well as to a Laplacian understanding of biological causality and randomness. After a short survey on the structures of determination, from Laplace to modern dynamics, we argue that both the metaphor and the model are causally inadequate, in particular when derived from the current empirical practices in Molecular Biology, based on the "differential method" (a mutation is observed or induced and its phenotypic consequences are observed). While referring to empirical evidence and theoretical writings in Biology, we will argue that the programming/deductive paradigm is theoretically unsound as causal and deductive frame for relating the genome to the phenotype, even from the point of view of Physics and Programming. This is in contrast to the physicalist and computational grounds that this paradigm pretends to propose. Two different notions of randomness as unpredictability, in Classical and Quantum Physics, will be briefly surveyed. We will hint to the need of a third concept of randomness that the unpredictability of the ecosystem seems to require in Biology. Finally, the familiar physical notion of "self-organized criticality" will be "extended" to an understanding of the long-lasting coherence structures of life, as "extended criticality", a conceptual frame for the analysis of the physical singularity of life. (work in collaboration with P.-E. Tendero and F. Bailly, see below) REFERENCES (see: http://www.di.ens.fr/users/longo ) Bailly F., Longo G. Mathématiques et sciences de la nature. La singularité physique du vivant. Hermann, Paris, 2006 (Introduction in English downloadable) Downloadable papers: Bailly F., Longo G. Randomness and Determination in the interplay between the Continuum and the Discrete. MSCS, (in press). Longo G., Tendero P.-E., The causal incompleteness of Programming Theory in Molecular Biology. Submitted for publication to BioEssays. (A preliminary and longer French version will appear as Conférence invitée, aux actes du colloque "Logique, informatique et biologie", Nice, 9-10 Décembre, 2005, to be published by Vrin, Paris, 2007.)
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